Device and method for image reconstruction at different X-ray energies, and device and method for X-ray three-dimensional measurement

Abstract

A device and a method for image reconstruction at different X-ray energies that make it possible to achieve image reconstruction with higher accuracy. A device for image reconstruction at different X-ray energies includes: an X-ray source 1 that irradiates a specimen to be imaged 2 with X-rays; an energy-dispersive detector 4 that detects a characteristic X-ray emitted from the specimen to be imaged 2 ; a signal processor that quantifies the peak of the characteristic X-ray detected by the detector 4 ; and an image reconstruction device that reconstructs an image on the basis of a signal from the signal processor.

What is claimed is: 
     
       1. A device for image reconstruction at different X-ray energies, comprising:
 an X-ray source that irradiates a specimen to be imaged with X-rays;
 an energy-dispersive detector that detects a characteristic X-ray emitted from the specimen to be imaged; 
 a signal processor that quantifies the peak of the characteristic X-ray detected by the detector; 
 an image reconstruction device that reconstructs an X-ray CT image at each of a plurality of energy levels on the basis of a signal from the signal processor; and 
 an image correction device that corrects the X-ray CT image at each of the plurality of energy levels such that a sinogram of the X-ray CT image at each of the plurality of energy levels converges to a corresponding correct sinogram. 
 
 
     
     
       2. The device according to  claim 1 , wherein the detector includes a plurality of sub-detectors arranged in a line or panel formation. 
     
     
       3. The device according to  claim 2 , wherein the sub-detectors are detectors that acquire the characteristic X-ray coming from each element of the specimen to be imaged as a radiation energy spectrum by photon counting. 
     
     
       4. The device according to  claim 1 ,
 wherein the detector acquires the characteristic X-ray coming from each element of the specimen to be imaged as a radiation energy spectrum, and 
 the signal processor converts the peak of the characteristic X-ray of each element obtained from the radiation energy spectrum into quantified data for each element by threshold value processing. 
 
     
     
       5. The device according to  claim 4 , wherein the image reconstruction device reconstructs an image for each element of the specimen to be imaged on the basis of the quantified data of the characteristic X-ray peak of each element from the signal processor and combines the images into one image thereby to acquire a three-dimensional image that includes information from the elements of the specimen to be imaged. 
     
     
       6. The device according to  claim 1 , wherein the image reconstruction device uses a sequential approximate reconstruction algorithm. 
     
     
       7. The device according to  claim 1 , further comprising a drive mechanism that causes the specimen to be imaged, which is disposed between the X-ray source and the detector, to rotate and translationally move. 
     
     
       8. The device according to  claim 1 , further comprising a monitor that displays an image reconstructed by the image reconstruction device. 
     
     
       9. A method for image reconstruction at different X-ray energies, comprising the steps of:
 irradiating a specimen to be imaged with X-rays; 
 detecting a characteristic X-ray emitted from the specimen to be imaged by an energy-dispersive detector; 
 quantifying a peak of the detected characteristic X-ray; 
 reconstructing an X-ray CT image at each of a plurality of energy levels on the basis of quantified data of the characteristic X-ray peak; and 
 correcting the X-ray CT image at each of the plurality of energy levels such that a sinogram of the X-ray CT image at each of the plurality of energy levels converges to a corresponding correct sinogram.